The Smart Phone Evolution Multi-radio devices l Cellular: 2G, 3G, LTE, WiMAX l Wireless: Wi-Fi, Bluetooth l GPS, A-GPS l Mobile TV, FM radio l Multiple integrated functions l Camera l Interfaces (USB) l Touchscreen, keyboard l Memory cards l Wireless charging l Built-in projector l NFC (coming soon)

Smartphone antenna design

Smartphone antenna design there are multiple antennas on each phone: Primary Cellular Antenna (Transmit and Receive) Diversity Cellular Antenna (Receive Only) GPS Antenna (Receive Only) WIFI Antenna (Transmit and Receive) NFC Antenna

The Smart Phone Evolution

shared antenna The different frequency bands for cellular, GPS, and WLAN connectivity create

three main coexistence problems and are a major challenge for RF signal filtering and processing in smartphones.

A GPS+WLAN extractor employs one bandpass filter each to permit the GPS and WLAN signals through to the GPS and WLAN port. A dual notch filter at the same frequencies is used to allow signals at all other frequencies through to the cellular receiver.

WIFI antenna is typically located on the top of the device (near the GPS antenna and diversity cellular antenna).

WIFI antenna will be the smallest antenna. A half-wavelength at 2.4 GHz is 6.25 cm

(2.5"), and a half-wavelength at 5 GHz is 3 cm or just over an inch. GPS antennas bandwidth is fairly small. The GPS frequency is 1.575 GHz, with

virtually no bandwidth

GPS antenna efficiencies are typically on the order of -3 dB to -9 dB..

A half-wavelength at GPS frequency (1.575 GHz) is about 9.5 cm or 3.75 inches

METHODS TO ELIMINATE EMI OR DESIGN METHODS FOR EMC The effective methods to eliminate EMI are

1. Shielding

2. Grounding

3. Bonding

4. Filtering

5. Isolation

6. Separation and orientation

7. Circuit impedance level control

8. Cable design

9. Cancellation techniques in frequency or time domain

10. Proper selection of cables, passive components

11. Antenna polarization control

12. Balancing

Physical aspects of more receive antennas

• Cell coverage• Network stability• Link and system capacity• Interference mitigation• power consumption

Active Antenna System

A cell phone 0.5 W output power the phone transmits, there is a loss of at least 50% for the antenna efficiency, and at least 50% for the radiation that is not directed to your head. Hence, we can safely take 0.125 W (=0.5*0.5*0.5)

Electromagnetic Effects: Heating

Reducing the harmful effect is the need of present day

Globally , a parameter known as Specific Absorption Rate (SAR)

SAR is defined as the power absorbed per mass of tissue and has unit of watts/kg

Human contact with radiations

PROBLEM STATEMENT Radiations from cell

phone devices produce heat in human body Strong need to reduce this harmful effectSpecific Absorption Rate (SAR) is a

measure of the rate at which energy is absorbed by the body when exposed to a radio frequency (RF) electromagnetic field

WHO DECIDES WHAT A SAFE EXPOSURE LEVEL IS?

Currently, two international safety

bodies have developed exposure

guidelines for workers and for the

general public: the International

Commission on Non-Ionizing

Radiation Protection (ICNIRP); and

the Institute of Electrical and

Electronics Engineers (IEEE).

The map shows information on the status of the effective radio frequency exposure limits applicable to mobile phones and similar devices.

EMC Tests for the Compliance Needs testing about

1) Intra-system EMC for stable operation, performance & quality

2) inter-system EMC for the protection of radio service (Radio law) and the safety from

danger regulation & certificateEMC

Electromagnetic Compatibility

EMIElectromagnetic Interference

CE (IEC/CISPR)Conducted Emission

∙ Voltage∙ Current

RS (IEC/TC77, ISO)Radiated Susceptibility

∙ Magnetic Fields∙ Electric Fields

RE (IEC/CISPR)Radiated Emission

∙ Magnetic Fields∙ Electric Fields∙ Conducted Power Disturbance

EMSElectromagnetic Susceptibility

CE (IEC/TC77, ISO) Conducted Susceptibility

∙ HF/LF∙ Surge, EFT Burst∙ ESD

Measuring SARSAR is critical to antenna design, if the SAR is too high the antenna must be changed.if the SAR is too high the transmit power is lowered

antenna positioning is critical. The antennas for mobile phones are typically on the bottom of the phone, to keep the radiating part of the phone as far as possible from the brain region.

methods for dropping the SAR include impedance matching changes and parasitic resonators

Parameters that can affect SAR include:

Types of radio service (cellular, PCS, , WLAN, etc.)

Types of modulations (CDMA, GMSK, TDMA, etc.)

Physical orientation to person

RF power level (in Watts or mW)

Changes to transmitter,antenna

To legally sell a cell phone to customers, the FCC limits the radiation you can receive from the phone when it is placed directly against your ear.

The FCC and SAR

Why Samsung Cell Phones Are Rated The Lowest Radiation Cell Phones

The Samsung Galaxy Note 2 smartphone has a maximum

SAR of 0.17 W/kg (watts per kilogram).

The SAR for the Apple iPhone 4S is 1.11, and for the

Motorola Droid Razr Maxx, it is 1.54 W/kg.

RF shielded flip cover cases

ConclusionUntil now, man has been absorbing

the harmful, unseen EM radiations

without even being aware of it, but

now, with rapid advent in

technology this RF Radiation

pollution has started having ill

effects on human health and health

of animals.

Hence, there is an urgent need to

take precautionary steps.